31 July 2013

Scrolling through the Orioles newsfeed the other day, an
article written by Derek Wetmore on the
team’s website caught my eye. The
article discussed the recent trend of Baltimore starters pitching deeper into
games, which gives the relievers in the bullpen more time to rest. It’s not breaking news to tell you that the
overuse of a bullpen is a bad thing, but I did find it curious that the team
would complain (complain is probably the wrong word to use here) about its bullpen
receiving too much time off.

Conventional wisdom states that overuse of a team’s bullpen can
lead to relievers becoming ineffective, particularly during the home stretch of
the long season. The most recent example
is the 2011 Atlanta Braves, who leaned on Craig Kimbrel, Jonny Venters, and
Eric O’Flaherty heavily throughout the year (each appeared in at least 78 games). This strategy worked well for Atlanta until September,
when the team finished with a 9-18 record, and blew an 8.5 game lead in the
wild card to the St. Louis Cardinals on quite possibly the greatest single day of baseball in history. Kimbrel and Venters were a key part of that
collapse, as Venters compiled a 5.11 ERA in the month, while Kimbrel had a 4.76
ERA along with 3 blown saves. Additionally, earlier this year, both O’Flaherty
and Venters underwent Tommy John surgery.
While their heavy usage likely played a part in their September 2011 struggles,
it’s unclear how much it contributed to Venters and O’Flaherty’s injuries (if
at all), but it is worth noting.

Back to the Orioles. As
manager Buck Showalter mentions in the article linked above, the line between
too much rest and overuse is a delicate balance. You don’t want to wear your guys down, but at
the same time, baseball is like everything else in life, you have to practice
to be good at it, and nothing can replace the experience of pitching in a live
game. At this point in the season, the
starting rotation ranks 18th in innings pitched, while the relievers
rank 12th. There’s room for
improvement, but they essentially seem to be in the middle of the pack. The addition of Scott Feldman to the rotation
in early July has certainly helped, as the rotation’s average innings per start
in July is the highest it’s been all year.

They’ve been even better since the All-Star break, averaging
6.43 IP per start. Combine the increased
innings of the starting pitchers with the extra days off at the All-Star break,
and you should have a very well rested bullpen.
But is that necessarily a good thing?

Let’s take a look at a graph that shows Baltimore’s bullpen
ERA and FIP associated with the days of rest the relievers have received. The number in parentheses included on the
x-axis represent the innings pitched in those situations.

In 2013 as a unit, the Orioles bullpen has performed best
after 5 days of rest, while they have performed worst after 3 days of
rest. However, the 9.1 innings pitched
with 5 days of rest is too small of a sample to confidently say that is the
preferred amount of rest. Additionally,
the entire analysis over 4 months of the 2013 season may be too small of a
sample. With that in mind, let’s see how
the Baltimore bullpen performance changed relative to days of rest in 2012 and
2011, and see if we can find any sort of pattern.

It’s interesting that both ERA and FIP spike upwards at 3
days of rest on all 3 graphs. This would
suggest that 0-2 days of rest would be optimal for bullpen performance. The
varied results following 4+ days of rest could be a result of the small sample of
innings pitched (innings pitched for 6+ days of rest are biased high, as
explained below).

Admittedly, this analysis is very basic, and it’s important
to remember that while these graphs tell us a lot, they don’t tell us
everything. First is that they
only tell us how often a reliever throws in back to back games (zero days
rest), but they don’t tell us how pitching with zero days rest multiple days in
a row affects the results. Additionally,
they don’t tell us who is pitching these innings. This is important because your best relievers
are more likely to be pitching more often with less rest (and yielding better
results), while the “mop up” guys will be pitching “mop up” innings, meaning
your worst pitchers should normally be pitching with more rest. Finally, since the number rest days only
looks at major league days of rest, it includes innings from recent minor
league call-ups who have probably pitched more recently than 6 days ago, therefore
artificially inflating the innings pitched in that category.

As basic as this study was, it could easily be expanded to
give more useful information. It could
include how pitching with zero days rest multiple days in a row affects results. It could be expanded to include all teams
over a longer period of time to give more confidence in the findings. Individual pitchers could be looked at to see
how each pitcher performs when given certain rest days. Or you could even get into the details and
see how rest days affect the velocity and movement of individual pitches, as
Josh Kalk attempted to do for the Hardball Times. It’s amazing how one simple question could
lead to so many different studies.

As for this study, it just reinforces the thought that Buck
Showalter knows what he’s talking about.
But you probably knew that already.

29 July 2013

I wrote a version of this article a few days ago for Baltimore Sports and Life. However, I wanted to share it here as well as my writing here will see an uptick over the upcoming playoff run for the Orioles. So, with some moderate excitement, I am back in a deadline deal sort of way.

Is there really anything more to say about the Orioles' acquisition of Francisco Rodriguez? I certainly think so and it does not have to do with the pall cast over the deal with the known and alleged incidents of violence that are attached to the team's new relief pitcher. No, I do not
wish to discuss my perspective Rodriguez pleading guilty to attempted
assault to avoid jail time when he attacked his at-the-time fiance’s
father or about the time he attacked Mets’ bullpen coach during a game
or the allegations of repeated abuse that the prosecution came up with
or about the Milwaukee abuse case that was dropped when his at-the-time
girlfriend (who was allegedly attacked) and the sole alleged witness (a
housekeeper) went back to Venezuela and were no longer around for the
trial.

What
I want to discuss is how this deal rates as a baseball acquisition. To what extent does Rodriguez improve this team. What are best case scenarios in a general sense using
simple numbers to see how big a deal acquiring Rodriguez was for the
success of the team. To do with, I want to assume the following:

With 58
games left, there are about 25 innings left for the 7th inning righty,
8th inning righty, and middle relief / junk inning righty.

Francisco Rodriguez is a 3.00 ERA pitcher (let’s assume he is really solid down the stretch).

Tommy Hunter and Darren O’Day are 4.00 ERA pitchers (let’s assume they
struggle down the stretch to the point that they are underperforming
their current ERAs of 2.80 and 2.20, respectively).

Jairo
Asencio and whoever are 6.00 ERA pitchers (this is likely a pessimistic
view as to what the default 4th righty in the pen could do).

So, here is what we get without Rodriguez using the above assumptions.

IP

ERA

Runs

7th

Tommy Hunter

25

4.00

11

8th

Darren O’Day

25

4.00

11

Junk

Jairo et al.

25

6.00

17

39

This is what happens with Francisco Rodriguez as the 8th inning righty, again, according to the set assumptions:

IP

ERA

Runs

7th

Darren O’Day

25

4.00

11

8th

Francisco Rodriguez

25

3.00

8

Junk

Tommy Hunter

25

4.00

11

30

These two tables note that the acquistion of Rodriguez saves the team nine run. That is roughly worth one win based on standard sabermetric practice (that number jumps around year to year). However, is it adequate to simply look at those nine runs and assume it is worth a win. Are runs more or less important are the end of the game or in situations where these pitchers pitch to the point where grouping it all together makes for unfair comparisons?

The Leverage Index suggests that maybe we need to drill down a bit further. To those of you who do not know, the Leverage Index calculates how important a situation is in a game based on the
number of outs, baserunners, men on base, and the score. A neutral
scenario would have a Leverage Index of one. A consequential
plate appearance would be greater than one. Here are the Leverage
Indices of Orioles relievers when they enter a game:

Those
numbers pass the sniff test. Johnson, O’Day, and Matusz are often
placed in on the mound in tough situations. Strop may seem like an outlier, but the team tried their best to keep him as a setup man and then 7th inning man until his performance found the team shipping him
to the Cubs. The point I am trying to make here is that even though the
different between the two assumed righty sets above amount to 9 runs, 6
of those runs are saved in junk innings that normally would have gone
to guys like Burnett, Johnson, Gausman, and, yes, Asencio. Those
scenarios were ones where the game was largely in the Orioles’ favor or
their opponents’. With that in mind, those runs given up in low leverage situations are not very meaningful because of the run differential in those game situations.

Instead, the important runs in the
optimistic scenario that was detailed earlier in this post would be the focused on the three runs that do not score thanks to
3.00 ERA Rodriguez on the mound instead of 4.00 ERA O’Day in the eighth inning, but we need to determine how valuable those runs might be. As mentioned earlier as well, a general
appreciation of what a run is worth (about 1/9th of a win) would suggest that having Rodriguez
is worth about a third of a win due to those three runs saved. However,
runs scored in high leverage situations are likely to be worth a
different amount than runs scored in less important situations

Here is the score differential of the July outings when O’Day entered the game:

Dif

Runs

July 24th

0

1

July 21st

2

0

July 19th

2

0

July 13th

-4

0

July 11th

1

0

July 9th

-3

1

July 7th

1

0

July 5th

1

0

July 3rd

0

0

Five
(or 56%) of his July outings were games where the differential in score
was 0 runs or the Orioles being up by 1. If that stays the same then
of those 25 8th innings to come, 14 of them will be games where the
score is tied or the team is holding on by one run. That difference now
is about 2 runs (slightly less) in what you could expect between a 3.00
pitcher and a 4.00 pitcher. That suggests than maybe the value of a
third of a run more important, might be lower than that.

However, assume that for 12 of those
innings pitched, Rodriguez and O’Day would be the same pitcher, but for
the other two innings Rodriguez would give up no runs and O’Day would give up a
run in each performance. Well, how does that impact win probability.

Visitor

Dif

Win Probability

1

85

0

48

-1

14

Home

Dif

Win Probability

1

89

0

63

-1

30

Why are the probabilities different? It almost all comes down to
the home team having two innings to score while the visitor having only
one. If we look at the worst case scenarios (as a vistor going +1 to
0; as a home team going 0 to -1), we have decreases in win probability
of 37% and 33%. In other words, not letting runs score in the worst
cases possible detailed above means a 3.00 pitcher is worth about 0.7
wins more than a 4.00 pitcher. In other words, the runs saved in the
8th inning in high leverage conditions are roughly twice as important
than they are in general based on the assumptions I have made here.

Where we are left is that under ideal
circumstances, it is probably safe to assume that the addition of
Rodriguez will benefit the team with an extra game in the win column, at
most. More likely though, his impact will be far less felt.
Differences in runs saved in high leverage innings will likely be rather
inconsequential and applying Hunter to even lower leverage innings will
likely be even more inconsequential.

In the end, the team gave
up a second tier prospect in Nicky Delmonico. A position player who was
100th ranked in Baseball America’s top 100 prospects has a 1 in 3
chance of being a useful starter in baseball. At best, Delmonico was
just south of 150th and probably no worse the 200th. More than likely
he will never make a dent on a MLB roster. Even more important,
Delmonico would have had zero impact on the Orioles in 2013 when they
are competing for a playoff spot. In other words, one would be pressed
to call him a meaningful prospect.

However, Delmonico does not
need to be a meaningful prospect to have value. I’d suggest that his
ability to augment a trade package is probably worth more than him being
traded straight up for a reliever who at best makes the 2013 Orioles a
+1 win team. It is difficult to ever know what is possible in trades
and it is an illness in the brain that us followers of the game tend to
want to believe in an abundance of trade opportunities, but I do think
that a package of Delmonico plus one would likely bring back to the
Orioles a player of greater importance than Rodriguez. Of course, this
contention is somewhat unfair. It is difficult for the addition of
Rodriguez to stand up against a comparison of something that does not
exist. The vagueness of the unknown is certainly a draw for many to
embrace and questioning Oriole front office authority has been a talent
that has been thoroughly developed over the past decade and a half.
That said, I maintain that the health of the franchise is better served
when second tier prospects are stacked instead of being doled out one at
a time.

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Contributors

Jon Shepherd - Founder/Editor@CamdenDepotStarted Camden Depot in the summer of 2007. By day, a toxicologist and by night a baseball analyst. His work is largely located on this site, but may pop up over at places like ESPN or Baseball Prospectus.

Matt Kremnitzer - Assistant Editor@mattkremnitzerMatt joined Camden Depot in early 2013. His work has been featured on ESPN SweetSpot and MASNsports.com.

Matthew Cassidy - WriterMatt joined Camden Depot before Spring Training in 2017. His love of music is surpassed only by his obsessions with food (unhealthy) and baseball statistics (totally healthy).

Patrick Dougherty - Writer@pjd0014Patrick joined Camden Depot in the fall of 2015, following two years writing for Baltimore Sports & Life. He is interested in data analysis and forecasting, and cultivates those skills with analysis aimed at improving the performance of the Orioles (should they ever listen).

Nate Delong - Writer@OriolesPGNate created and wrote for Orioles Proving Ground prior to joining Camden Depot in the middle of 2013. His baseball resume includes working as a scorer for Baseball Info Solutions and as a Video Intern for the Baltimore Orioles. His actual resume is much less interesting.

Matt Perez - Writer@FanOfLaundryMatt joined Camden Depot after the 2013 season. He is a data analyst/programmer in his day job and uses those skills to write about the Orioles and other baseball related topics.

Joe Reisel - WriterJoe has followed the Norfolk Tides now for 20 seasons. He currently serves as a Tides GameDay datacaster for milb.com and as a scorer for Baseball Info Solutions (BIS). He is computer programmer/analyst by day.

Joe Wantz - WriterJoe is a baseball and Orioles fanatic. In his spare time, he got his PhD in political science and works in data and analytics in Washington DC.